Apparatuses for reducing plant material, such as a stump grinder, are often used for cutting and/or grinding plant material (such as tree roots, tree stumps, etc.) in the ground for purposes of reducing or removing the plant material from the ground. Many stump grinders include a boom supporting a cutting assembly having a cutting wheel, and rotational motion of the cutting wheel is typically driven by a drive shaft powered by a motor. During operation of the stump grinder, particularly while cutting/grinding the plant material in the ground, the cutting wheel may encounter material such as burlap string, twine, long tree roots, wires, cables, and/or the like. In some instances, the material may wrap around rotational components of the stump grinder as the drive shaft and the cutting wheel rotates. This can adversely affect the rotational movement and/or operation of the cutting wheel, the drive shaft, or both. Where the stump grinder utilizes a hydraulic drive system supported by the boom, material wrapped around the drive shaft could also interfere with the hydraulic drive motor. For example, the material could impose certain angular stresses on the drive shaft that could result in rupturing of a seal formed between the drive shaft and the hydraulic drive motor. Rupturing of the seal could result in undesirable leakage of hydraulic fluid from the motor.
Accordingly, there remains an opportunity to provide an apparatus for reducing plant material that solves the problem(s) identified above.